Carina Nebula

The Spitzer Space Telescope captured this infrared view of the Carina Nebula. Highlighted above is the 'South Pillar' region of the star-forming nebula — a region reminiscent of the Hubble Space Telescope's image of the Eagle Nebula's 'Pillars of Creation.'

Courtesy NASA / JPL / Caltech / N. Smith (University of Colorado, Boulder).

The first day of the American Astronomical Society's meeting in Minneapolis, Minnesota, yielded a flurry of exciting new science results. But a dark cloud of anxiety looms over the conference as astronomical research in the United States faces an uncertain future in a tightening fiscal environment.

A team led by Nathan Smith (University of Colorado) presented one of the major science results: a new Spitzer Space Telescope infrared image of the Carina Nebula. This nebula, which is visible to the naked eye in the Southern Hemisphere, harbors dozens of unstable, extremely massive stars. These stars blow winds at up to 1,600 kilometers per second (4 million miles per hour) — with disastrous consequences for their surroundings.

In this new infrared mosaic detailing the South Pillar region of the nebula, Smith's team used Spitzer to uncover more than 17,000 newly formed stars. The massive star Eta Carinae (outside the picture's top) is stripping away the nebula with ultraviolet radiation and powerful winds, carving out a giant, irregular hot bubble. As the bubble expands, it compresses the gas it meets into nodules, streamers, and bright cloud rims. These in turn collapse to form new stars. The densest regions form pillars like those famously imaged by the Hubble Space Telescope in the Eagle Nebula (M16). "What we are seeing in the Spitzer image," says Smith, "are a bunch of elongated structures, with stars forming at the head, that are all aiming back in the same direction toward Eta Carinae."

. Using computer simulations, Sourav Chatterjee (Northwestern University) and two colleagues have offered the most probable explanation for the bizarre planet discovered in globular cluster M4 — the planet distantly orbiting an unusual, close binary consisting of a pulsar and a white dwarf. Chatterjee's group proposes that the planet first formed around a normal star. When the planet and star ventured into the crowded environment of the globular's core, where close stellar encounters are common, it swung perilously near a binary system consisting of a neutron star and a normal star. The binary gravitationally snared the planet from its original host star and ejected the host star in the process. Eventually, the normal star orbiting the pulsar evolved into a white dwarf, leaving the planet in orbit around two collapsed stellar remnants.

. Our neighbor the Andromeda Galaxy (M31) just got a lot bigger than astronomers once thought. Scott Chapman (Caltech) and his team report observations of M31 with the 10-meter Keck II Telescope in Hawaii. They found roughly 3,500 faint, outlying stars rotating along with the galaxy's main disk at distances exceeding 220,000 light-years from M31's center. This "extended disk" is probably the product of one or more smaller galaxies merging with M31. More information will appear in the August Sky & Telescope.

. Even with new science results being presented in many fields, hallway conversations have focused on concerns for the future of national astronomy facilities in the U.S. With flat or declining budgets expected for the next decade, the National Science Foundation (NSF) has proposed a review of all of America's federally funded visual, radio, and solar observatories. The hope is to find $30 million before fiscal year 2008 to fund new telescopes. Not wanting to cut back on grants to researchers, the NSF has been forced to consider closure or privatization of some of its facilities. Each NSF-funded observatory will have to write a letter to the NSF this summer to make its case for continued operation. This fall an NSF committee will discuss which facilities might be cut. The final decision will be delivered by November.

Stay tuned to throughout the week as more news from the American Astronomical Society meeting develops.


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